A massive leak of financial documents reveals hidden assets and deals of the world's wealthy and powerful. In collaboration with the International Consortium of Investigative Journalists, FRONTLINE, in Pandora Papers, examines secret finance overseas and in the U.S. that has enabled the wealthy to hide their assets from the government. Massacre in El Salvador examines the horrors of what happened when U.S.-trained and -equipped Salvadoran soldiers killed some 1,000 civilians, many of them children. FRONTLINE, Retro Report and ProPublica's investigation follows the ongoing fight for justice for the horrific 1981 attack on the village of El Mozote and surrounding areas, and how today the case against high-ranking military officials is faltering under Salvadoran President Nayib Bukele.